LINQ to XML实现XML文档的增删改查
1、实例中的XML文档（Books.xml）
Harry Potter
J K. Rowling
2005-08-15
29.99
Learning XML
Erik T. Ray
2003-10-18
39.95
XQuery Kick Start
James McGovern
2005-06-25
49.99
2、 创建图书信息实体类（BookInfo.cs）
///
/// 图书信息实体类
///
public class BookInfo
{
public int BookId { set; get; } //图书ID
public string Title { set; get; } //图书名称
public string Category { set; get; } //图书分类
public string Author { set; get; } //图书作者
public DateTime PublishDate { set; get; } //出版时间
public Double Price { set; get; } //销售价格
}3、 创建图书信息业务逻辑类（BookInfoBLL.cs）
using System.Linq;
using System.Xml.Linq;public class BookInfoBLL
{
private string _basePath = AppDomain.CurrentDomain.SetupInformation.ApplicationBase + @"/xml/Books.xml"; //XML文件路径
///
/// 创建图书XML文档（创建）
///
public void CreateBookXml()
{
//获取图书列表
List bookList = GetBookList();
//创建XML文档
XDocument bookDoc = new XDocument();
//创建声明对象
XDeclaration xDeclaration = new XDeclaration("1.0", "utf-8", "yes");
bookDoc.Declaration = xDeclaration; //指定XML声明对象
//创建bookstore节点
XElement xElement = new XElement("bookstore");
foreach (BookInfo book in bookList)
{
//创建book节点
XElement bookXml = new XElement("book");
//添加属性
bookXml.Add(new XAttribute("id", book.BookId));
bookXml.Add(new XAttribute("category", book.Category));
//添加子节点
bookXml.Add(new XElement("title", book.Title));
bookXml.Add(new XElement("author", book.Author));
bookXml.Add(new XElement("publishDate", book.PublishDate.ToString("yyyy-MM-dd")));
bookXml.Add(new XElement("price", book.Price));
//将book节点添加到bookstore节点中
xElement.Add(bookXml);
}
//保存文件
bookDoc.Add(xElement);
bookDoc.Save(_basePath);
}
///
/// 获取图书列表(查询)
///
/// 参数条件
/// 图书列表
public List GetBookInfoList(BookInfo param)
{
List bookList = new List();
XElement xml = XElement.Load(_basePath);
var bookVar = xml.Descendants("book"); //默认查询所有图书
if (param.BookId != 0) //根据图书ID查询
{
bookVar = xml.Descendants("book").Where(a => a.Attribute("id").Value == param.BookId.ToString());
}
else if (!String.IsNullOrEmpty(param.Category)) //根据图书类别查询
{
bookVar = xml.Descendants("book").Where(a => a.Attribute("category").Value == param.Category);
}
else if (!String.IsNullOrEmpty(param.Title)) //根据图书名称查询
{
bookVar = xml.Descendants("book").Where(a => a.Element("title").Value == param.Title);
}
bookList = (from book in bookVar
select new BookInfo
{
BookId = int.Parse(book.Attribute("id").Value),
Category = book.Attribute("category").Value,
Title = book.Element("title").Value,
Author = book.Element("author").Value,
PublishDate = DateTime.Parse(book.Element("publishDate").Value),
Price = double.Parse(book.Element("price").Value)
}).ToList();
return bookList;
}
///
/// 增加图书信息（新增）
///
///
///
/// 修改图书信息（修改）
///
///
///
/// 删除图书信息（删除）
///
///
///
/// 获取图书列表
///
/// GetBookList()
{
List bookList = new List();
//创建图书1
BookInfo book1 = new BookInfo() {
BookId = 1,
Category = "CHILDREN",
Title = "Harry Potter",
Author = "J K. Rowling",
PublishDate = new DateTime(2005,08,15),
Price = 29.99
};
bookList.Add(book1);
//创建图书2
BookInfo book2 = new BookInfo()
{
BookId = 2,
Category = "WEB",
Title = "Learning XML",
Author = "Erik T. Ray",
PublishDate = new DateTime(2003,10,18),
Price = 39.95
};
bookList.Add(book2);
//创建图书3
BookInfo book3 = new BookInfo()
{
BookId = 3,
Category = "WEB",
Title = "XQuery Kick Start",
Author = "James McGovern",
PublishDate = new DateTime(2005,6,25),
Price = 49.99
};
bookList.Add(book3);
return bookList;
}
}